The FHWA’s RT&E program role is to provide leadership at conducting highway-related research, development, deployment, and training activities to address current and emerging needs facing our nation’s transportation system. The program is responsible for developing and delivering the solutions needed to meet current challenges and foresee future needs, addressing them proactively and effectively. FHWA’s Research and Development initiatives are focused on advancing the state of the art. Technology Transfer and Training and Education Initiatives focus on advancing the state of the practice through the deployment of new technology and innovations.
The new technologies and innovations that result from FHWA’s RT&E program are typically non-proprietary, and effective technology transfer requires that State DOTs and municipalities, and the private-sector contractors that they hire, learn about and use these new technologies and innovations. FHWA’s leadership role signifies a commitment to working collaboratively with its partners in defining the direction of and developing the FHWA roadmaps needed to achieve results, especially since these partners may at times be the ones implementing the technologies and innovations developed.
The success of new technologies and products developed through FHWA research ultimately depends on their acceptance by States, industry, and other stakeholders. Innovation delivery is another key step in the R&T life cycle. Through demonstration projects, education and training programs, manuals and other publications, and hands-on assistance, FHWA works to support the deployment of new, cost-effective, and high-performing technologies. Deployment efforts are coupled with assessment initiatives, which complete the R&T life cycle by evaluating the impact of new processes and technologies.
FHWA provides key support to the delivery of technologies and innovations. By bringing together the FHWA Resource Center, National Highway Institute (NHI), and Technology Partnerships Programs under one office, FHWA strengthened its ability to deliver vital services more strategically. The Resource Center and its Technical Service Teams facilitate technology deployment and technical assistance, NHI provides critical training opportunities, and the Technology Partnerships Programs offer education and local and tribal technology assistance.
The Technical Service Teams provide expertise and innovative technical assistance to help State and local agencies successfully adopt and deploy new technologies in such areas as construction and project management, finance services, operations, pavement and materials, safety and design, and structures. The work of the teams is bolstered by NHI, which offers more than 300 courses across 17 program areas to advance the performance of the transportation workforce. A growing number of courses are available online, meeting the need for training even as State and local agencies face tighter budgets. Partnerships are also key, as the Technology Partnerships Programs support the training, technical assistance, and technology deployment efforts of the Local Technical Assistance Program and Tribal Technical Assistance Program centers.
The three main components of the RT&E program are as follows:
The HRD program highlights FHWA’s leadership in developing a comprehensive, nationally-coordinated FHWA highway research and technology program, engaging and cooperating with other highway research stakeholders. The HRD program performs research activities associated with safety, infrastructure preservation and improvements, environmental mitigation and streamlining, livability considerations, operations, and policy. The research conducted aims to collect information that ultimately provides transportation policymakers tools and products that allows them to make accurate decisions that improve the nation’s quality of life. The HRD program includes FHWA’s advanced and applied research, and facilitates national and international coordination and collaboration to leverage knowledge and develop solutions to address current and emerging highway transportation needs.
Safety. Research and development activities support comprehensive and sustainable safety programs. Activities emphasize data-driven analysis of roadway-related safety considerations and specific improvement in four crash areas: roadway departure, intersection, pedestrian, and speeding. The program conducts rigorous evaluations to determine what safety improvements can be expected with the introduction of countermeasure designs or operations. All design or operational changes are assessed from a human factor perspective to eliminate or minimize unexpected consequences of change. FHWA works in cooperation with NHTSA and FMCSA to develop tools and technologies to reduce crashes and improve highway and intermodal transportation safety.
Infrastructure. FHWA conducts problem-focused research, development, and communications outreach activities to preserve the existing investment in our Nation’s highway infrastructure and to build for the future through the application of advanced technologies that improve infrastructure integrity. Infrastructure-related research focuses on three major areas: pavements, bridges and structures, and asset management. This work includes: a) development of metrics to assess the performance of infrastructure over the longer term; b) research and development of technologies and techniques to assure that the Nation’s infrastructure is world class from a standpoint of longevity, safety, performance, climate-change mitigation, and sustainability; and c) leadership to ensure effective follow-up and deployment of the improvements developed, particularly those that will speed construction and reduce congestion caused by construction.
Planning and Environment. Activities in this program area include carrying out short and long-term livability initiatives to improve project delivery and enhance communities that are impacted by surface transportation projects; developing comprehensive strategies to minimize the impact of transportation investment on the environment; adjust to changing climate conditions, advancing state of the practice for data collection, geographic information systems applications, and travel forecasting; and providing technical assistance and forums, best practices, and training to assist States, Metropolitan Planning Organizations, local public agencies and other partners and stakeholders in planning and delivering surface transportation projects.
Operations. The Operations program conducts research on the application of cutting-edge technologies to move people and goods better, quicker, and safer. The primary focus of Operations activities is on congestion relief solutions. This work will mitigate the impacts of recurring congestion, as well as deal more effectively with non-recurring events that cause congestion, such as traffic incidents, work zones, adverse weather conditions and planned special events. Activities also include conducting applied research to develop the next generation of traffic management systems and models, and researching specific technologies that can improve the performance of its services and support to the Intelligent Vehicle Initiative and the Cooperative Intersection Collision Avoidance Initiative. HRD Operations also pursues a broad range of activities designed to improve freight movement and reduce freight-related congestion throughout the transportation network.
Policy. The Policy program analyzes emerging issues in the transportation community, including climate change, public-private partnerships, highway revenues, performance management, authorizing legislation, and a host of other issues. The program also supports data collection on motor fuels, motor vehicles, licensed drivers, roadway characteristics, pavement conditions, travel trends, and travel behavior. Policy data collection and forecasting efforts provide the foundation on which program administration, policy analysis and implementation, and legislative support all rely. The Policy area is responsible for the development of the Infrastructure Investment Needs Report, which promotes the ongoing development of engineering and economic analytical tools and related products to assess the current and future conditions and performance of the Nation’s highways and bridges. Policy initiatives include the International Highway Transportation Outreach Program, which provides better knowledge of technology and best practices put in place in other countries that can improve the U.S. surface transportation system. The initiatives also support implementation of these innovations, leveraging resources to enable the U.S. to benefit from investments made by foreign counterparts, and creating business opportunities for the U.S. private sector. The Policy program also supports innovative program delivery solutions in areas such as Public-Private Partnerships and alternative funding mechanisms for highways.
Next Generation Research & Technology. The Next Generation Research & Technology (R&T) program is responsible for leading the development and coordination of the FHWA components of a national highway research agenda to provide policy-makers and the research community information needed to address critical knowledge gaps, collaboration opportunities, and accelerate innovation and technology deployment to meet future highway transportation needs. The FHWA provides the unique national leadership and support required to accomplish this goal and meet the collective needs and national priorities recognized by highway research and technology stakeholders. FHWA has been working with these stakeholders to establish an on-going framework or process to identify national research needs that should be the focus of FHWA’s program; improve coordination among researchers; and identify potential opportunities for synergy among research entities. Initial work on creating the framework for developing a highway research agenda is underway, and resources are needed to continue this effort to achieve the goal of an enhanced research agenda, based on a sustained, collaborative process, and reflective of our national needs and priorities. Next Generation R&T also encompasses the Exploratory Advanced Research (EAR) Program, which conducts longer-term, higher-risk research with the potential for dramatic breakthroughs in surface transportation. Key elements of the EAR program are to obtain information from the very large number of basic and advanced research and development activities outside of the highway R&D community for possible exploitation, adaptation and eventual application to the highway industry. Next Generation R&T also supports the operation of the Turner-Fairbank Highway Research Center (TFHRC), a Federally-owned and operated research facility in McLean, Virginia that provides State and local governments, FHWA, and the world highway community with advanced and targeted applied research and development related to new highway technologies. Research conducted at and managed by this facility focuses on providing solutions to complex technical problems through the development of more economical, safe, and environmentally sensitive designs; more efficient, quality controlled constructions practices; and more durable materials.
After innovations and technologies have gone through an initial testing and evaluation process, and they are ready to be put through a more refined, conclusive testing, or they are ready to be deployed, these technologies are advanced into the TIDP program, where final analysis, marketing, communications, and promotional activities are conducted to accelerate its adoption by state DOTs and other government entities or beneficiaries. This aspect of the innovation lifecycle has in the past been insufficiently funded, which has resulted in a number of market-ready technologies that could be highly beneficial to the industry being under-utilized. Thus, FHWA is establishing a separate program area that will aim at advancing deployment-ready technologies resulting from the HRD program, or take market-ready technologies developed by other entities and support their accelerated implementation by State DOTs or other stakeholders.
The goal of the newly-created TIDP is to accelerate the delivery and deployment of innovation and technology. The program aims to concentrate on the growing need to significantly accelerate the adoption of proven, high-payoff, innovative practices and technologies that will significantly improve safety, efficiency, reliability and performance of the current highway transportation system. The TIDP will shorten project planning and delivery time, advance longer-lasting highway innovations and technologies to accomplish the fast construction of efficient and safe highways and bridges, improve safety during and after construction, reduce recurring and non-recurring congestion, improve freight movement and enhance the quality of the highway infrastructure. The TIDP will speed up the adoption of innovative technologies by the surface transportation community, providing creative programs, technical assistance, and resources to state and local transportation agencies to implement market-ready technologies. The TIDP will embrace stakeholder participation, monitoring, evaluation, documentation, and open dissemination of results. It will allow for the modification or upgrade of existing innovations and technologies to ensure widespread adoption and benefit by the highway community.
FHWA TIDP will also work with AASHTO, the States, the Transportation Research Board and others on the implementation of the Strategic Highway Research Program (SHRP 2) results. The purpose of SHRP 2 is to conduct concentrated, results-oriented applied research focusing on solving the top problems in the area of highway safety, reliability, capacity, and renewal. The research program has been carried out by the Transportation Research Board (TRB) in consultation with AASHTO and FHWA, and is now reaching the results implementation phase.
Finally, TIDP will provide a conduit to accelerate technology and innovation delivery through FHWA’s recently launched second Every Day Counts initiative (EDC2). The Every Day Counts Initiative identifies under-utilized market-ready technologies with high pay-offs and accelerates their deployment and acceptance throughout the Nation.
T&E is responsible for training the current and future transportation workforce, transferring knowledge quickly and effectively to and among transportation professionals, and providing education solutions throughout the full innovation lifecycle. The T&E program provides a wide variety of services and products, including:
FHWA's continued commitment to highway research and the implementation of ground-breaking technology is changing the way roads, bridges, and other facilities are planned, designed, built, and maintained across the country. This commitment ultimately delivers a safer, more reliable transportation system that is both effective and environmentally sustainable. The success of the RT&E program can be illustrated through the following examples of innovations that support DOT strategic goals:
Although conducting a solid Research and Development program creates technologies and innovations with the potential to improve the state of the practice, the ultimate measure of that success is through the effective implementation of those advances.
EDC is FHWA’s flagship initiative to accelerate the implementation of new technologies and innovations. Performance goals and metrics were established for each of the initiatives in the first round of EDC, and similar performance goals and metrics are being developed for the launch of the second round of EDC. These goals include statements such as:
Goal Example A: FHWA will ensure that [x%] of States are trained in [a technology] by [date].
Goal Example B: [x%] of State DOTs will have adopted [certain practice or technology] on Federal-aid projects by [date].
Goal Example C: For States that adopt [certain practice or technology], [x%] of the Federal-aid projects initiated after [data] will utilize [that practice or technology].
Goal Example D: By [date], [x] State DOTs will have a specification and/or contractual language to allow [certain practice or technology] on Federal-aid projects.
Goal Example E: By [date], at least [x] State DOTs will have established and achieved [a target use level for a practice or technology].
Goal Example F: By [date], at least [x practices or technologies] will have been [designed or constructed] nationally.
Goal Example G: By [date], at least [x] State DOTs will have authorized use of at least [x practice or technology].
Below are a few examples of FHWA’s successful research and technology transfer efforts.
FHWA continues to be at the forefront of research into the design and application of roundabouts, which are one-way, circular intersections where traffic flows around a center island. With intersection-related crashes accounting for 47 percent of all crashes in the United States and 21 percent of all traffic fatalities, improving intersection safety is an important priority for FHWA. The results from roundabouts in use to date are significant. A National Cooperative Highway Research Program (NCHRP) Report, Roundabouts in the United States (NCHRP Report No. 572), found that the installation of roundabouts led to a 35 percent reduction in total crashes and a 76 percent reduction in crashes causing injuries or fatalities. Other studies have also reported impressive safety benefits. To support the implementation of roundabouts across the country, FHWA published Roundabouts: An Informational Guide in 2000. When it was issued, fewer than 100 modern roundabouts existed in the United States. With about 2,000 roundabouts located throughout the country today, TRB released Roundabouts: An Informational Guide, Second Edition (NCHRP Report No. 672) in 2010. Jointly funded by FHWA, the report officially updates and supersedes the 2000 Guide. A newly launched FHWA Roundabouts Peer-to-Peer Program, meanwhile, is providing technical assistance to State DOTs and others as they implement the technology. California, Connecticut, Illinois, Massachusetts, and Missouri have received assistance to date. NHI also offers training on “Modern Roundabouts: Intersections Designed for Safety” (Course No. FHWA-NHI-380096).
Pavement smoothness is not only vital to building better roadways but a key factor in ensuring that sidewalks and curb ramps are accessible to individuals with disabilities and meet the standards of the Americans with Disabilities Act (ADA). However, the traditional ADA survey process for assessing the condition of sidewalks and curb ramps is time-consuming and does not offer jurisdictions precise data. The Ultra-Light Inertial Profiler (ULIP), an instrumented Segway® developed by FHWA for pavement surface evaluation, offers an accurate and cost-effective solution. FHWA provided technical support as Bellevue, Washington, used the ULIP to conduct an ADA evaluation of existing physical barriers for persons with disabilities. Use of the technology: 1) cut Bellevue’s costs from more than $1 million down to $285,000 and 2) resulted in more precise data on conditions such as pavement roughness and defects, helping the city to better prioritize its remediation efforts. The cities of San Marcos, Clovis, and San Carlos in California are also using the ULIP for ADA assessment in 2011.
More than 20 years after data collection began for the Long-Term Pavement Performance (LTPP) program, the benefits and products generated by the program continue to change pavement design and management worldwide. The LTPP database has played a critical role in the development and evaluation of every major pavement design methodology developed over the past 20 years. This includes the 1993 and 1998 AASHTO design procedures, the Superpave® mix design system, and the DARWin-ME™ pavement design software. This software gives engineers improved tools for specifying the optimum mix, layer configuration, and thickness for new and rehabilitated pavements. DARWin-ME would not have been possible without LTPP data for many inputs. Calibrated nationally with LTPP test sections, DARWin-ME has shown significant reductions in the initial cost for heavily trafficked pavement designs, and its use is expected to generate annual savings of $1 billion. Beyond overall design procedures, the LTPP data have supported and will continue to support model development and validation for a wide array of pavement performance predictors and indicators.
The program has monitored the performance of nearly 2,500 in-service pavement test sections throughout the United States and Canada, including 758 test sections that are still being monitored today. These test sections represent a range of climatic and soil conditions. The data collected now form the largest and most comprehensive pavement database in the world. LTPP data have been translated into an array of products and tools for pavement engineers, including data collection procedures, a new falling weight deflectometer (FWD) calibration system, an updated FWD calibration protocol, and equipment protocols for traffic data collection. The FWD calibration system provides a method to assure that data collected to assess the structural condition of pavements will be accurate and consistent. A nondestructive testing device, the FWD imparts a dynamic load to the pavement surface that is similar to that of a single heavy moving wheel load. The resulting pavement deflection can then be measured. This deflection data combined with the pavement layer thickness can be used to help analyze the remaining service life of a pavement. These and other advancements resulting from LTPP research are detailed in a new report, Long-Term Pavement Performance Program: Accomplishments and Benefits 1989–2009 (Pub. No. FHWA-HRT-10-071).
The LTPP program’s LTPP Computed Parameter: Dynamic Modulus study developed estimates of the dynamic modulus of hot-mix asphalt (HMA) layers on LTPP test sections following the models used in the Mechanistic-Empirical Pavement Design Guide. Adopted by AASHTO in 2008, the new guide enables transportation agencies to better predict pavement performance over time and make more informed decisions when designing pavements. Additionally, LTPP*, a user-friendly software, was developed to facilitate dynamic modulus computations. This will allow transportation agencies to more accurately characterize the strength and load resistance of their asphalt mixes, resulting in better and longer lasting pavements. Nearly 400 copies of the software have been distributed to State agencies and others. More information on the software and study findings can be found in the new TechBrief, LTPP Computed Parameter: Dynamic Modulus (Pub. No. FHWA-HRT-11-018).
LTPP advancements will also benefit future pavement professionals. Several universities have introduced curricula that include LTPP data, for example. To encourage use of the data, FHWA and the American Society of Civil Engineers (ASCE) sponsored an International Contest on LTPP Data Analysis in 2010. The contest included categories for both undergraduate and graduate students, partnerships, and curriculum. Looking to the future, additional products and tools could result from efforts to optimize pavement treatment selection, assess the impact of the environment on pavement performance, and compare the performance of new materials to conventional materials.
Many factors, including project time constraints, demand for longer pavement design lives, and environmental, social, and economic considerations, are leading the concrete paving industry to come up with new ways to proportion and optimize concrete mixtures. Additionally, many concrete material choices are available today that add complexity to the mixture proportioning process. With all of these changes, the industry needed a tool for concrete mixture optimization that could isolate properties of interest and simplify the approach to the mixture proportioning process based on site-specific conditions. In response to this need, FHWA developed the Concrete Mixture Performance Analysis System (COMPASS). With this Windows®-based application system, a user can optimize the performance of a concrete mixture in a particular environment by properly selecting material constituents, such as types of aggregates, cementitious materials, and admixtures, that will benefit properties identified as important to a particular environment or project type. The user can also determine the appropriate gradation and material constituent proportions that will enhance the performance of a mixture. These benefits will result in longer-life pavements.
As transportation agencies balance the need to rehabilitate and reconstruct existing highways with the goals of reducing congestion and improving safety, accelerated construction is more important than ever. A new software tool, Construction Analysis for Pavement Rehabilitation Strategies (CA4PRS), assists agencies in making accelerated construction a reality. The software was developed under an FHWA pooled fund study by the Institute of Transportation Studies at the University of California at Berkeley. California, Minnesota, Texas, and Washington participated in the study. All States can now obtain the software and training at no charge.
CA4PRS can be used to identify optimal highway rehabilitation strategies that balance the construction schedule with inconvenience to drivers and transportation agency costs. The program’s scheduling module estimates project duration, while its traffic module quantifies the impact of work zone lane closures on the traveling public. The cost module estimates total project cost (including construction, traffic handling, and supporting costs). A growing number of States are using CA4PRS, including California, Utah, and Washington. Approximately 20 States have obtained the software. The California Department of Transportation (Caltrans), for example, used it in the design stage of a recently completed project on I-15 in Ontario to select the most efficient rehabilitation strategy for the roadway. Caltrans’ use of the software on a previous project on I-15 in Devore cut construction and traffic control costs by 25 percent, saving $6 million, and an additional $2 million in road user costs. “A key benefit of using CA4PRS is that it allows us to get in and get out faster, reducing both the length of construction projects and traffic congestion,” said Michael Samadian of Caltrans.
Following the collapse of the I-35W Bridge in Minneapolis, Minnesota, in 2007, FHWA developed a Bridge Inspection Nondestructive Evaluation Showcase to give bridge owners, managers, and inspectors training in the latest nondestructive evaluation (NDE) tools and systems. NDE methods can be used to assess existing conditions in highway bridges during routine inspections, supplementing visual inspections and improving the overall reliability of bridge evaluations. The showcase is now offered through NHI (Course No. FHWA-NHI-130099). FHWA is also conducting numerous other studies intended to advance NDE practice and help develop and deploy new tools and technologies that aid in assessing the condition of the Nation’s physical infrastructure. Work underway includes researching NDE methods as well as developing resources for bridge owners and inspectors. A current research project is focusing on developing an advanced method of measuring corrosion and section loss in gusset plates, with an emphasis on multiple plates and areas that are not visible for inspection. An ongoing project is investigating using response-based analysis of in-service bridges to increase the accuracy of load ratings. One benefit of this increased accuracy is to minimize load restrictions for bridges. These research projects and other NDE methods that range from simple to highly advanced will be documented in FHWA’s forthcoming NDE Web Manual. The manual, which will be hosted on the FHWA Web site, will feature information on NDE methods and link the methods with the inspection situations where they should be used.
FHWA’s RealCost software is a tool for performing life cycle cost analysis (LCCA) for pavement selection. The software can also be used for bridges and structures. LCCA provides a cost comparison between two or more competing design alternatives that produce equivalent benefits for the project being analyzed, evaluating agency and user costs over the life of the various alternatives. Because LCCA focuses on costs required over the life of an asset to maintain it above some minimum performance level, the lowest cost alternative is not necessarily the one with the lowest cost of initial construction. Using RealCost, agencies can analyze up to six design alternatives simultaneously. Up to four different traffic distributions, such as for a weekday or weekend, can also be defined and selected. Currently available in Version 2.5, which was released in 2010, the software calculates life cycle values for both agency and user costs associated with construction and rehabilitation. Numerous States have adopted RealCost for pavement LCCA and several, including California, Colorado, Florida, and Washington, have formally incorporated it into their pavement type selection policy or process. FHWA continues to enhance the RealCost software, incorporating user feedback and research findings. A new version of the software is expected to be released in 2012.
As transportation agencies seek to build sustainable highways that meet development and economic growth needs, while reducing impacts on the environment and consumption of natural resources, tools are needed to help agencies quantify sustainability and support their decisions. Released in 2010, FHWA’s Sustainable Highways Self-Evaluation Tool will provide valuable assistance to State DOTs and Metropolitan Planning Organizations (MPOs) as they work to make their highway projects more sustainable. With support from FHWA’s flexible, cross-functional research funding, the tool was developed in cooperation with State and local transportation agencies and organizations such as AASHTO and ASCE. States and MPOs can use it to evaluate their projects and practices and rate them using a consistent set of evaluation criteria and scores.
This unique tool addresses the full life cycle of a highway project, from planning through construction to operations and maintenance. Sustainability is measured through goals and credits for sustainable highway practices, projects, and programs. Each credit describes a particular practice, provides methods for implementing it, and includes examples where it has been successfully applied. The self-evaluation tool includes 68 credits, organized into system planning, project development, and operations and maintenance. Some agencies may use the sustainability tool to learn about how others are addressing sustainability or to find out more about certain sustainability practices that can be applied to a project, while other agencies may use it to track the performance of projects over time. Available in a beta version online at www.sustainablehighways.org, the tool offers users maximum, hands-on flexibility. Through a pilot testing initiative, FHWA will continue to refine and improve it.
Recycling asphalt pavement creates a cycle of reusing materials that optimizes the use of natural resources. Reclaimed asphalt pavement (RAP) reduces the need to use virgin aggregate, which is a scarce commodity in some areas of the United States, and cuts the energy and transportation costs needed to obtain the aggregate. It also reduces the amount of costly new asphalt binder required in the production of asphalt paving mixtures. The state of the practice for RAP use in the United States, as well as best practices for increasing the use of RAP in asphalt pavement mixtures while maintaining high-quality pavement infrastructure, is detailed in a new FHWA report, Reclaimed Asphalt Pavement in Asphalt Mixtures: State of the Practice (Pub. No. FHWA-HRT-11-021). The report provides useful information on RAP percentages and asphalt binder grade selection, mix design considerations, and performance of RAP asphalt mixtures.
From 2007 to 2009, about half of States reported increased use of RAP, with the average percentage of RAP used in HMA around 15 percent. Analyses by FHWA have shown that the performance and life of pavements containing up to 30 percent RAP is similar to virgin pavements containing no RAP. The ability to use 30 percent RAP in asphalt mixtures, compared to no RAP, can result in cost savings of more than $5 per ton of asphalt. Research led by FHWA has also shown that up to 20 percent RAP can be used in an HMA mixture without having to make changes to the asphalt binder. Using 20 percent RAP compared to 15 percent RAP results in cost savings of at least $1.25 per ton of asphalt. Based on the amount of HMA and warm mix asphalt (WMA) produced in 2010 and the amount of RAP used in HMA and WMA, this could result in savings of $125 million annually.
TFHRC’s new multimodal Transportation Operations Laboratory contains test beds for developing data resources, transportation concepts and analysis, and cooperative vehicle-highway interfaces. Offering a foundation for the future, the lab’s research will explore how innovative technologies can dramatically change and improve the performance of the Nation’s transportation system. The lab’s concepts and analysis test bed, for example, will be used to conduct “what-if” simulations to assess the impact of different technologies and policies. Research into vehicle-highway interfaces, meanwhile, will explore how traffic signals can “talk” to cars and mobile devices and cars can then “talk” to other cars and traffic signals about where they are and how fast they are going. This research could lead to significant decreases in delays and a reduction in the number of crashes that occur during stop-and-go traffic.
Operations research that will use the Cooperative Vehicle-Highway Testbed (CVHT) in FHWA’s new Transportation Operations Laboratory includes the Signal Phase and Timing (SPaT) Interface Definition and Prototype, which will define a common two-way interface between vehicle systems, mobile devices, and traffic signal controllers. This would enable applications such as warning drivers they are about to violate a red light and optimizing traffic flows through intersections, which can reduce emissions and fuel usage. The first two prototype controllers to use this new interface will be tested in the CVHT in late 2011 and early 2012.
FHWA is also supporting the procurement of roadside equipment that will enable wireless communications between vehicles and infrastructure for the Connected Vehicle Safety Pilot, which is being led by the Intelligent Transportation Systems (ITS) Joint Program Office of the U.S. Department of Transportation’s (U.S. DOT) Research and Innovative Technology Administration. Beginning in 2011 and running through the first half of 2013, this major research initiative will test how drivers in real-world conditions will respond to wireless safety messages targeted to them based on their specific position, situation, or vehicle type. These messages could include warnings such as “Use Caution, Icy Roads Ahead” or “Stop! Red Light Ahead” and address crashes associated with driving too fast for the conditions or driver distraction.
FHWA researchers are using step-frequency ground-penetrating radar (SF-GPR) to develop a nondestructive method for detecting and assessing inductive loop sensors that are embedded in roadway surfaces. The SF-GPR technology offers advanced subsurface three-dimensional imaging capabilities. The sensors being assessed indicate the presence or movement of vehicles and provide information that supports such traffic management applications as signal control and freeway mainline roadway and ramp control. Malfunctioning sensors can prevent traffic signals from sensing the presence of vehicles, which can be both frustrating for drivers and delay or prevent the display of green signal indicators to motorcyclists and bicyclists. Since research began in 2006 under a Small Business Innovation Research project, FHWA has improved the GPR detection and resolution capability and made significant steps in advancing the technology to the point where it can be commercialized.
FHWA highway research is creating a better, safer driving experience for today, but it is also looking at the infrastructure that will define tomorrow. From cutting-edge technologies inconceivable a generation ago to “smart” pavements and bridges that are just around the corner, the next generation of transportation has already begun.
The Long-Term Bridge Performance (LTBP) program is leading the way toward a better future for bridge performance. The program will collect, maintain, and study high-quality, quantitative performance data for a representative sample of bridges nationwide. These bridges will feature many structural types and materials, as well as variations in geometry, age, traffic volume, truck loads, and climatic conditions. Data collected by the program will support a better understanding of how and why bridges deteriorate, how to best prevent or mitigate deterioration, and how to most effectively focus the development of the next generation of bridge management tools. Pilot studies to assess program protocols and data management systems are now being conducted at seven bridges across the country. Located in California, Florida, Minnesota, New Jersey, New York, Utah, and Virginia, the pilot bridges represent both a broad geographic distribution and a cross section of the bridges on which the LTBP program will focus. The program will concentrate on the types of bridges heavily represented in the U.S. bridge population, including highway and interchange overpasses and bridges over minor waterways. The pilot phase is currently underway and will be completed in 2011, with the longer-term data collection phase to follow. While the data collection will occur over an extended period of time, an immediate payoff from the program will be the ability to integrate data from nondestructive testing and monitor bridge deterioration.
As the Nation looks to build longer lasting bridges and more rapidly renew its highway infrastructure, the use of high-strength and high-performing materials is more important than ever. For more than 10 years, FHWA’s structural concrete R&D program has worked to take concrete to new levels with the implementation of ultra-high performance concrete (UHPC). Exhibiting superior properties such as exceptional durability, high compressive strength, and long-term stability, UHPC components can facilitate accelerated construction and allow for the use of longer spans. States such as Iowa, New York, and Virginia are now beginning to use the new technology. In Buchanan County, Iowa, for example, the construction of the Jakway Park Bridge received a boost with the successful use of a new type of UHPC bridge girder developed through the FHWA R&T program. This was the first bridge in the country to be built using the UHPC technology, demonstrating the viability of the concept from design, through construction, and into everyday use.
UHPC research focal areas are advancing, including through a Transportation Pooled Fund project being conducted in partnership with the New York State Department of Transportation (NYSDOT) and the Iowa Department of Transportation. The project is evaluating the performance of novel field-cast UHPC connections linking prefabricated bridge girders to precast concrete bridge decks. While the use of modular bridge deck components can produce higher quality, more durable bridge decks, the required connections have often been lacking, diminishing the overall system performance. The new UHPC connection eliminates the conflict points between the deck reinforcing bars and the girder shear connectors, allowing for easy field assembly. NYSDOT hopes to use the concept in a highway interchange reconstruction project in 2011.
The story of UHPC and the unique solutions it offers is told in a new FHWA TechNote, Ultra-High Performance Concrete (Pub. No. FHWA-HRT-11-038).
Rapid deployment of proven technology and solutions to speed up project delivery are at the heart of FHWA’s new Every Day Counts (EDC) initiative. The EDC initiative is designed to identify and deploy proven, ready-to-go innovation aimed at shortening project delivery, enhancing roadway safety, and protecting the environment. Teams from FHWA are working with State, local, and industry partners to implement the EDC technologies and to achieve better, faster, and smarter ways of doing business. Priority technologies include many developed or advanced through FHWA research, such as warm mix asphalt (WMA), prefabricated bridge elements and systems (PBES), Adaptive Signal Control Technology (ASCT), and the Geosynthetic Reinforced Soil Integrated Bridge System (GRS-IBS).
ASCT adjusts signal timing to account for the variability in traffic demand that conventional traffic signals cannot accommodate, thereby improving traffic congestion and safety. Locations that have used this technology include Anne Arundel County, Maryland; San Ramon, California; San Marcos, California; Los Angeles, California; Bellevue, Washington; and Ann Arbor, Michigan.
The Safety EdgeSM technology provides a simple but effective solution to reduce pavement edge-related crashes and help save lives. By shaping the edge of a pavement to 30 degrees, the Safety Edge helps mitigate the problem of vertical drop-off, enabling vehicles to return to the paved road smoothly and easily.
WMA encompasses a variety of technologies that allow asphalt to be produced and then placed on the road at lower temperatures than the conventional HMA method. The lower temperatures may result in cost savings and reduced greenhouse gas emissions because less fuel is required. WMA is a proven technology that improves compaction, which then improves pavement performance, reduces fuel and energy usage, and increases worker comfort by reducing exposure to high temperatures and odors. WMA also has the potential to extend the construction season, allowing projects to be delivered in a timelier manner. TFHRC staff conducted early experiments when WMA technologies emerged and have been active participants in subsequent research and the deployment of WMA across the Nation.
FHWA has also supported research on PBES, as well as deployment of the new technology. The prefabricated systems can be manufactured offsite at a prefabrication plant or adjacent to the project site by the contractor, under controlled conditions, and brought to the bridge location ready to install. The use of PBES, ranging from superstructures or substructures to totally prefabricated bridges, offers both faster and safer bridge construction and better quality. PBES can also reduce costs and the environmental impact of projects. FHWA’s Connection Details for Prefabricated Bridge Elements and Systems manual (Pub. No. FHWA-IF-09-010) provides transportation agencies, contractors, and consultants with information on the state of the practice for accelerated bridge construction across the country.
In States such as Ohio and New York, GRS-IBS technology is revolutionizing bridge building by alternating layers of compacted local soil and sheets of geotextile fabric reinforcement to build abutments and provide support for the structure. Researchers at the U.S. Forest Service and the Colorado Department of Transportation (CDOT) pioneered the early development of the GRS technology. FHWA then worked with CDOT to further refine it. Today, FHWA is continuing to refine and broaden the applicability of the technology. The result is bridges that are both extremely durable and cost effective, with costs potentially reduced by 25 to 60 percent. The GRS-IBS method also blends the roadway into the superstructure to create a jointless interface between the bridge and the approach roadways, alleviating the common “bump” caused by differential settlement between bridge abutments and approach roadways. GRS-IBS can be built with readily available materials, using common construction equipment, and without the need for highly skilled labor.
New FHWA publications continue to advance the deployment of the GRS-IBS technology, including the Geosynthetic Reinforced Soil Integrated Bridge System Interim Implementation Guide (Pub. No. FHWA-HRT-11-026) and the Geosynthetic Reinforced Soil Integrated Bridge System Synthesis Report (Pub. No. FHWA-HRT-11-027). The guide takes engineers through the site selection, design, and construction process for GRS-IBS, while the companion report substantiates the design method and presents case histories for GRS-IBS bridges built to date.